1. Field of the Invention
The present invention relates to a method of approach to the lateral cervical facet for the purposes of spondylosyndesis or arthoplasty techniques as well as related devices.
2. Description of the Background
Human spinal degeneration is a natural result of aging and may lead to a medical condition known as spinal stenosis in which the spinal canal narrows and compresses the spinal cord and neural structures. Spinal stenosis is often accompanied or even caused by a herniated intervertebral disk. Patients suffering from the condition often experience significant pain and limited range of motion and mobility. Laminectomy is a surgical procedure for treating spinal stenosis in which one or both lamina are removed, often along with the spinal process, in order to relieve the pressure on the spinal cord and the related pain. Unfortunately, this procedure suffers from one major drawback, namely that it can compromise the stability of the spine, particularly when performed in the cervical region of the spine but also in the lumbar and thoracic regions as well.
Cervical facet fusion is a procedure in which the facet joints between two or more vertebra are joined together to stabilize the spine and eliminate motion which may contribute to spondylosis, or continued degeneration, and prevent progressive deformity. Cervical facet fusion is commonly performed in conjunction with laminectomy. Toward this end, recent technological advances have facilitated disc replacement and have paved the way for potential facet replacement. One of the major contraindications for disc arthroplasty is degeneration of the facet. By replacing the facet or resurfacing it, patients can benefit from this emerging technology.
The standard approach for decompressive laminectomy, facet fusion and/or facet replacements is the posterior approach, and may be performed through variety of methods. The classic method involves passing wires through drill holes in the articular processes and binding two longitudinal struts of bone to the posterior columns of the articular processes. Another technique uses lateral mass screws that are connected via a metal rod. However, regardless of the method used, the posterior approach for posterolateral cervical facet fusion is time-consuming, results in resection of important connective tissue and musculature, involves moderate blood loss and often results in the patient suffering from shoulder pain for a significant period after surgery. Posterior approach patients also usually require inpatient hospital care for 2 to 3 days, require drains and experience high incidence of surgical site infection.
A variety of devices from different manufacturers have been developed for utilization in spinal surgeries such as facet fusion. Many of these devices are intended for fusion or fixation of the vertebra in the cervical region and elsewhere. These devices commonly consists of one or more plates and screws, pegs, or rods with fixating connectors that may be joined to the bone in order to stabilize the spine. Other devices take the form of a staple. Considerable effort has been expended on preventing the counter-rotation and withdrawal of screws as well as the ability of the devices to secure adjacent vertebra. Considerably less effort has been expended on making such devices less intrusive and quicker to implant (while still maintaining efficacy).
Although the noted spinal fixation devices as well as others have furthered technological development, none are done through lateral cervical approach and none provide a small profile of fixation, decompression or arthroplasty. It would thus be advantageous to provide a cervical staple, screw fusion fixation or arthroplasty for lateral cervical facet joint that: (1) allows for a more precise and a much smaller profile of fixation than prior art devices, (2) imposes less blood loss, (3) minimizes surgical time (4) avoids traction on the esophagus and trachea as in the anterior approach, (5) is minimally invasive, (6) is lightweight, and (7) is inexpensive to manufacture and sell to provide for widespread use.
A novel lateral approach is herein proposed for facet decompression, fusion or arthroplasty that avoids many of the drawbacks of the known approaches. The lateral approach is done through a minimally invasive method, offers direct access to the facet joint, provides secure stabilization, and permits early mobilization of the patient.
The present applicant has submitted a copending patent application for facet replacement using the lateral approach for the purpose of inserting a resurfacing material.